Item Type: Keyhole Cutter Material: Alloy Steel Total Length: Approx. 46mm / 1.8in Handle: Approx. 12.7mm / 0.5in Diameter of Cutter Head: Approx. 9.52mm / 0.4in Uses: Generally Used for Wood Perforation, Spherical Door Tip Installation, Drawer Tip, Plastic Products, Wood, Plywood, Etc Package List 1 x Keyhole Cutter 1 x Plastic Box 1.Cannot be used for electric drills and drilling rigs; each time (or after 2 hours of continuous use), remember to use lubricating oil for maintenance before use2.Please allow 02 cm error due to manual measurement. Thanks for your understanding 1Durable, the head adopts an arcshaped curve design, which is conducive to chip removal and higher perforation efficiency 2Designed for handheld and desktop routers, not for electric drills and rigs. Small size, easy to handle 3High hardness, accurate positioning, glossy cutting, impact resistance, high toughness 4Cutting long T-slots and making keyhole slots for hanging and other purposes 5Generally used for wood perforation, spherical door tip installation, drawer tip, plastic products, wood, plywood, etc